Răspuns:
Explicație pas cu pas:
D₇={ 1, 7 ,-1 ,-7 }......................D₇=divizorii lui 7
2x+1=1
2x=1-1
2x=0
x= 0 ∈ Z
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2x+1=7
2x=7-1
2x= 6
x= 6:2
x=3 ∈Z
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2x+1=-1
2x=1-1
2x=-2
x= -2:2
x= -1 ∈Z
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2x+1=-7
2x=-7-1
2x=-8
x= -8:2
x= - 4 ∈Z
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A= { -4 ,- 1 , 3 ,0 }
-
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D₉= { 1,3,9 ,-1,-3 ,-9 }
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2x-3=1
2x=1+3
2x=4
x=4:2
x=2 ∈Z
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2x-3= -3
2x=-3+3
2x=0
x=0:2
x=0 ∈Z
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2x-3=9
2x=9+3
2x= 12
x= 12:2
x=6 ∈Z
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2x-3= -9
2x=-9+3
2x= -6
x= -6:2
x= -3 ∈Z
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B={2,0,6,-3 }
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A∩B={0}
A∪B={-4,-1, 3,0 , 2,-3 ,6,}
